/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.messaging.simp.config;

import org.springframework.lang.Nullable;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.SubscribableChannel;
import org.springframework.messaging.simp.stomp.StompBrokerRelayMessageHandler;
import org.springframework.util.Assert;

/**
 * Registration class for configuring a {@link StompBrokerRelayMessageHandler}.
 *
 * @author Rossen Stoyanchev
 * @since 4.0
 */
public class StompBrokerRelayRegistration extends AbstractBrokerRegistration {

    private String relayHost = "127.0.0.1";

    private int relayPort = 61613;

    private String clientLogin = "guest";

    private String clientPasscode = "guest";

    private String systemLogin = "guest";

    private String systemPasscode = "guest";

    @Nullable
    private Long systemHeartbeatSendInterval;

    @Nullable
    private Long systemHeartbeatReceiveInterval;

    @Nullable
    private String virtualHost;

    private boolean autoStartup = true;

    @Nullable
    private String userDestinationBroadcast;

    @Nullable
    private String userRegistryBroadcast;


    public StompBrokerRelayRegistration(SubscribableChannel clientInboundChannel,
                                        MessageChannel clientOutboundChannel, String[] destinationPrefixes) {

        super(clientInboundChannel, clientOutboundChannel, destinationPrefixes);
    }


    /**
     * Set the STOMP message broker host.
     */
    public StompBrokerRelayRegistration setRelayHost(String relayHost) {
        Assert.hasText(relayHost, "relayHost must not be empty");
        this.relayHost = relayHost;
        return this;
    }

    /**
     * Set the STOMP message broker port.
     */
    public StompBrokerRelayRegistration setRelayPort(int relayPort) {
        this.relayPort = relayPort;
        return this;
    }

    /**
     * Set the login to use when creating connections to the STOMP broker on
     * behalf of connected clients.
     * <p>By default this is set to "guest".
     */
    public StompBrokerRelayRegistration setClientLogin(String login) {
        Assert.hasText(login, "clientLogin must not be empty");
        this.clientLogin = login;
        return this;
    }

    /**
     * Set the passcode to use when creating connections to the STOMP broker on
     * behalf of connected clients.
     * <p>By default this is set to "guest".
     */
    public StompBrokerRelayRegistration setClientPasscode(String passcode) {
        Assert.hasText(passcode, "clientPasscode must not be empty");
        this.clientPasscode = passcode;
        return this;
    }

    /**
     * Set the login for the shared "system" connection used to send messages to
     * the STOMP broker from within the application, i.e. messages not associated
     * with a specific client session (e.g. REST/HTTP request handling method).
     * <p>By default this is set to "guest".
     */
    public StompBrokerRelayRegistration setSystemLogin(String login) {
        Assert.hasText(login, "systemLogin must not be empty");
        this.systemLogin = login;
        return this;
    }

    /**
     * Set the passcode for the shared "system" connection used to send messages to
     * the STOMP broker from within the application, i.e. messages not associated
     * with a specific client session (e.g. REST/HTTP request handling method).
     * <p>By default this is set to "guest".
     */
    public StompBrokerRelayRegistration setSystemPasscode(String passcode) {
        Assert.hasText(passcode, "systemPasscode must not be empty");
        this.systemPasscode = passcode;
        return this;
    }

    /**
     * Set the interval, in milliseconds, at which the "system" relay session will,
     * in the absence of any other data being sent, send a heartbeat to the STOMP broker.
     * A value of zero will prevent heartbeats from being sent to the broker.
     * <p>The default value is 10000.
     */
    public StompBrokerRelayRegistration setSystemHeartbeatSendInterval(long systemHeartbeatSendInterval) {
        this.systemHeartbeatSendInterval = systemHeartbeatSendInterval;
        return this;
    }

    /**
     * Set the maximum interval, in milliseconds, at which the "system" relay session
     * expects, in the absence of any other data, to receive a heartbeat from the STOMP
     * broker. A value of zero will configure the relay session to expect not to receive
     * heartbeats from the broker.
     * <p>The default value is 10000.
     */
    public StompBrokerRelayRegistration setSystemHeartbeatReceiveInterval(long heartbeatReceiveInterval) {
        this.systemHeartbeatReceiveInterval = heartbeatReceiveInterval;
        return this;
    }

    /**
     * Set the value of the "host" header to use in STOMP CONNECT frames. When this
     * property is configured, a "host" header will be added to every STOMP frame sent to
     * the STOMP broker. This may be useful for example in a cloud environment where the
     * actual host to which the TCP connection is established is different from the host
     * providing the cloud-based STOMP service.
     * <p>By default this property is not set.
     */
    public StompBrokerRelayRegistration setVirtualHost(String virtualHost) {
        this.virtualHost = virtualHost;
        return this;
    }

    /**
     * Configure whether the {@link StompBrokerRelayMessageHandler} should start
     * automatically when the Spring ApplicationContext is refreshed.
     * <p>The default setting is {@code true}.
     */
    public StompBrokerRelayRegistration setAutoStartup(boolean autoStartup) {
        this.autoStartup = autoStartup;
        return this;
    }

    /**
     * Set a destination to broadcast messages to user destinations that remain
     * unresolved because the user appears not to be connected. In a
     * multi-application server scenario this gives other application servers
     * a chance to try.
     * <p>By default this is not set.
     *
     * @param destination the destination to broadcast unresolved messages to,
     *                    e.g. "/topic/unresolved-user-destination"
     */
    public StompBrokerRelayRegistration setUserDestinationBroadcast(String destination) {
        this.userDestinationBroadcast = destination;
        return this;
    }

    @Nullable
    protected String getUserDestinationBroadcast() {
        return this.userDestinationBroadcast;
    }

    /**
     * Set a destination to broadcast the content of the local user registry to
     * and to listen for such broadcasts from other servers. In a multi-application
     * server scenarios this allows each server's user registry to be aware of
     * users connected to other servers.
     * <p>By default this is not set.
     *
     * @param destination the destination for broadcasting user registry details,
     *                    e.g. "/topic/simp-user-registry".
     */
    public StompBrokerRelayRegistration setUserRegistryBroadcast(String destination) {
        this.userRegistryBroadcast = destination;
        return this;
    }

    @Nullable
    protected String getUserRegistryBroadcast() {
        return this.userRegistryBroadcast;
    }


    protected StompBrokerRelayMessageHandler getMessageHandler(SubscribableChannel brokerChannel) {

        StompBrokerRelayMessageHandler handler = new StompBrokerRelayMessageHandler(
                getClientInboundChannel(), getClientOutboundChannel(),
                brokerChannel, getDestinationPrefixes());

        handler.setRelayHost(this.relayHost);
        handler.setRelayPort(this.relayPort);

        handler.setClientLogin(this.clientLogin);
        handler.setClientPasscode(this.clientPasscode);

        handler.setSystemLogin(this.systemLogin);
        handler.setSystemPasscode(this.systemPasscode);

        if (this.systemHeartbeatSendInterval != null) {
            handler.setSystemHeartbeatSendInterval(this.systemHeartbeatSendInterval);
        }
        if (this.systemHeartbeatReceiveInterval != null) {
            handler.setSystemHeartbeatReceiveInterval(this.systemHeartbeatReceiveInterval);
        }
        if (this.virtualHost != null) {
            handler.setVirtualHost(this.virtualHost);
        }

        handler.setAutoStartup(this.autoStartup);

        return handler;
    }

}
